diff --git a/addons/mcs_payroll_localization/hooks.py b/addons/mcs_payroll_localization/hooks.py
index c32ff67..65df1f8 100644
--- a/addons/mcs_payroll_localization/hooks.py
+++ b/addons/mcs_payroll_localization/hooks.py
@@ -51,23 +51,16 @@ class PayrollSetup:
 
     def _ensure_base_structure(self, company, categories):
         base = self.Structure.search([("code", "=", "BASE"), ("company_id", "=", company.id)], limit=1)
+        values = {
+            "name": "Base Payroll Structure",
+            "code": "BASE",
+            "company_id": company.id,
+            "rule_ids": [(6, 0, [])],
+        }
         if not base:
-            base = self.Structure.create({
-                "name": "Base Payroll Structure",
-                "code": "BASE",
-                "company_id": company.id,
-                "rule_ids": [(6, 0, [
-                    self._rule(company, "Base Basic Salary", "BASE_BASIC", 10, categories["BASIC"], """
-result = contract.wage
-""").id,
-                    self._rule(company, "Base Gross", "BASE_GROSS", 100, categories["GROSS"], """
-result = categories.BASIC + categories.ALW
-""").id,
-                    self._rule(company, "Base Net Salary", "BASE_NET", 300, categories["NET"], """
-result = categories.BASIC + categories.ALW + categories.DED
-""").id,
-                ])],
-            })
+            base = self.Structure.create(values)
+        else:
+            base.write(values)
         return base
 
     def _rule(self, company, name, code, sequence, category, python, register=False):
@@ -127,7 +120,7 @@ result = contract.wage * 0.50
 result = contract.wage * 0.20
 """),
             self._rule(company, "Special Allowance", "ALLOW", 30, categories["ALW"], """
-result = contract.wage - categories.BASIC - categories.ALW
+result = contract.wage * 0.30
 """),
             self._rule(company, "Gross", "GROSS", 100, categories["GROSS"], """
 result = categories.BASIC + categories.ALW